1 Combine the browned beef with the chopped onion, kidney beans, French dressing, water, chile and garlic. Simmer for 15 minutes. Season with salt to taste. Allow to cool for several hours, if possible, so that flavors blend. Skim off extra fat.
2 Fry tortillas in deep fat or oil. Fry on one side, turn, pinch up corners and hold with tongs to form cup shapes; or fry flat and crisp.
3 Combine the lettuce (both kinds) with the purple cabbage, scallions, tomatoes and 1 1/2 cups of the cheese. Reheat the meat mixture.
4 Combine both mixtures and spoon generously into the crisp-fried tortilla cups. Garnish servings with avocado slices and remaining cheese. Stick a tostado into the top of each serving. Serve with a basket of crisp tostados.